Metal powder has wide applications in electronic component manufacturing, electroplating, and batteries of the electronic industry, chemical catalysis, jewelry and other industries. With development of the electronic components in the direction of miniaturization and high performance, higher requirements have been put forward for sintering activity, dispersity, sphericity, crystallinity and other performances of the metal powder. Currently, preparation of metal powder includes physical and chemical methods. The physical method includes an atomization method, a vapor phase evaporation condensation method, a grinding method, and so on, and the chemical method includes a liquid phase reduction method, an electrochemical deposition method, an electrolysis method, and so on. Due to the problems of high cost and low yield with the physical method, the currently widely used method is the chemical liquid phase reduction method, that is, metal is reduced by a chemical reaction from a metal-containing salt solution or metal oxide, such as CN1301205, Sinter-Active Metal and Alloy Powders for Powder Metallurgy Applications and Methods for Their Production and Their Use. The China Patent CN101597777 discloses a method of reducing metal oxide or salt into metal by the electrolysis method.